Mechanical press system and method of removing salt using the same

ABSTRACT

A method of removing salt from a dendritic mixture includes loading the dendritic mixture into a mechanical press system. The dendritic mixture includes a metallic dendrite and salt dispersed within the metallic dendrite. The dendritic mixture is heated to liquefy the salt without volatilizing one or more metals of the metallic dendrite. The dendritic mixture is also compressed to obtain a fluidic mixture and an ingot of the metallic dendrite. The fluidic mixture may include molten salt and residual metallic dendrite. The fluidic mixture may be filtered to separate the residual metallic dendrite from the molten salt.

BACKGROUND

1. Field

The present disclosure relates to systems and methods for removing saltsfrom electrolytically-reduced metals.

2. Description of Related Art

During a fuel fabrication process, metal oxides may be obtained fromspent nuclear material and electrolytically reduced to their metallicform. The resulting metal from the electrolytic reduction step may be inthe form of a dendritic structure (e.g., cake), which resembles a porousmetal sponge with a relatively high surface area. As a result, thedendritic structure will also have a relatively large amount of saltadhered to and included therein from the electrolytic reduction step.

To remove the salt from the dendritic structure, a cathode processor isconventionally used to subject the mixture to relatively hightemperatures to vaporize the salt. However, the relatively hightemperatures will also vaporize volatile contaminants and radioactivematerials within the mixture, which requires relatively expensiveequipment to clean up the offgas from such a process while alsoincreasing the risk of an accidental release of such materials.

BRIEF DESCRIPTION OF EXAMPLE EMBODIMENTS

A mechanical press system may include an upper press body including acurved bottom portion and an upper lip portion surrounding the curvedbottom portion; a first heater within the upper press body; a lowerpress body aligned below the upper press body, the lower press bodyincluding a top portion and a lower lip portion surrounding the topportion, the upper press body and lower press body configured to cometogether during a compression state and configured to move apart duringa decompression state; a second heater within the lower press body; anda containment band configured to rest on the lower lip portion of thelower press body and to surround the upper lip portion of the upperpress body during the compression state and configured to separate fromthe upper press body and the lower press body during the decompressionstate.

A method of removing salt from a dendritic mixture may include loadingthe dendritic mixture into a mechanical press system, the dendriticmixture including a metallic dendrite and the salt dispersed within themetallic dendrite; heating the dendritic mixture to liquefy the saltwithout volatilizing one or more metals of the metallic dendrite; andcompressing the dendritic mixture to obtain a fluidic mixture and aningot of the metallic dendrite, the fluidic mixture including moltensalt and residual metallic dendrite.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the non-limiting embodimentsherein may become more apparent upon review of the detailed descriptionin conjunction with the accompanying drawings. The accompanying drawingsare merely provided for illustrative purposes and should not beinterpreted to limit the scope of the claims. The accompanying drawingsare not to be considered as drawn to scale unless explicitly noted. Forpurposes of clarity, various dimensions of the drawings may have beenexaggerated.

FIG. 1 is a schematic view of a loading phase of a method of removingsalt from a dendritic mixture using a mechanical press system accordingto an example embodiment.

FIG. 2 is a schematic view of a compression phase of a method ofremoving salt from a dendritic mixture using a mechanical press systemaccording to an example embodiment.

FIG. 3 is a schematic view of a decompression phase of a method ofremoving salt from a dendritic mixture using a mechanical press systemaccording to an example embodiment.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

It should be understood that when an element or layer is referred to asbeing “on,” “connected to,” “coupled to,” or “covering” another elementor layer, it may be directly on, connected to, coupled to, or coveringthe other element or layer or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon,” “directly connected to,” or “directly coupled to” another elementor layer, there are no intervening elements or layers present. Likenumbers refer to like elements throughout the specification. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

It should be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers, and/or sections should not be limited by these terms. Theseterms are only used to distinguish one element, component, region,layer, or section from another region, layer, or section. Thus, a firstelement, component, region, layer, or section discussed below could betermed a second element, component, region, layer, or section withoutdeparting from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like) may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” may encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing variousembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exampleembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, example embodiments should not be construed aslimited to the shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing. Forexample, an implanted region illustrated as a rectangle will, typically,have rounded or curved features and/or a gradient of implantconcentration at its edges rather than a binary change from implanted tonon-implanted region. Likewise, a buried region formed by implantationmay result in some implantation in the region between the buried regionand the surface through which the implantation takes place. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to illustrate the actual shape of a region of adevice and are not intended to limit the scope of example embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, including those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

FIGS. 1-3 show a mechanical press system and a method of removing saltusing the same. Referring to FIGS. 1-3, a mechanical press systemaccording to an example embodiment may include an upper press body 120including a curved bottom portion and an upper lip portion surroundingthe curved bottom portion. A first heater 122 may be arranged within theupper press body 120. A lower press body 110 may be aligned below theupper press body 120. The lower press body 110 may include a top portionand a lower lip portion 112 surrounding the top portion. The upper pressbody 120 and lower press body 110 are configured to come together duringa compression state (FIG. 2) and configured to move apart during adecompression state (FIG. 3). A second heater 116 and a third heater 118may be arranged within the lower press body 110. A containment band 106is configured to rest on the lower lip portion 112 of the lower pressbody 110 and to surround the upper lip portion of the upper press body120 during the compression state (FIG. 2). The containment band 106 isalso configured to separate from the upper press body 120 and the lowerpress body 110 during the decompression state (FIG. 3).

In further detail, FIG. 1 is a schematic view of a loading phase of amethod of removing salt from a dendritic mixture using a mechanicalpress system according to an example embodiment. Referring to FIG. 1, adendritic mixture 102 is supplied to the mechanical press system with adispensing apparatus 100. The containment band 106 and the lower pressbody 110 together define a receptacle for receiving the dendriticmixture 102. The dendritic mixture 102 may be a combination of metallicdendrite with salt dispersed within the metallic dendrite. Although thedendritic mixture is illustrated as being dispensed in a first direction104, it should be understood that the dispensing may be performed inanother direction depending on the system design. A sieve 114 may bealigned below a periphery of the lower press body 110. Thehole/opening/perforation size of the sieve 114 is less than an averageparticle size of the metallic dendrite of the dendritic mixture 102.

The top portion and the lower lip portion 112 of the lower press body110 form a notch therebetween. The notch is configured to receive andhold the containment band 106 during the loading state (FIG. 1) and thecompression state (FIG. 2). The lower lip portion 112 may be in a formof continuous structure that completely surrounds the top portion of thelower press body 110. When the lower lip portion 112 is in a form ofcontinuous structure, openings may be provided in the bottom of thenotch to allow molten salt to pass during the compression state.Alternatively, the lower lip portion 112 may be in a form of a pluralityof intermittent structures that are spaced around the top portion of thelower press body 110 in a manner that is adequate to receive and holdthe containment band 106. For instance, two or more (e.g., three, four,five, six, seven, eight, etc.) intermittent structures may be evenlyspaced around the top portion of the lower press body 110, althoughexample embodiments are not limited thereto. The length of theintermittent structures may be relatively long so as to be greater thanthe space between them. In another example, the length of theintermittent structures may be relatively short so as to be less thanthe space between them.

The head of the lower press body 110 may be in a form of a disc, whereinthe area of the top surface is less than that of the opposing bottomsurface. As a result, a side surface of the head of the lower press body110 may slope outwards from the top surface to the opposing bottomsurface. Consequently, a cross-section of the head of the lower pressbody 110 may have a trapezoidal shape as shown in FIG. 1. In such anexample, the lower lip portion 112 may be mounted on the side surface ofthe head of the lower press body 110. The angle between the upper sidesurface of the head of the lower press body 110 and the lower lipportion 112 is not particularly limited as long as the resulting notchis sufficient to support and maintain the integrity of the containmentband 106 during the compression state. Alternatively, the lower pressbody 110 may have a continuous curved or rounded top portion instead ofone that has a binary change from a flat top surface to a sloping sidesurface.

The containment band 106 may be in a form of an open-ended cylinder,although other shapes are possible as long as the containment band 106fits in the notch formed by the top portion and the lower lip portion112 of the lower press body 110. The fit between the containment band106 and the lower press body 110 should be adequate to prevent themetallic dendrite of the dendritic mixture from passing therebetweenduring the loading state. The containment band 106 also includes ahandle structure 108 on an exterior surface of the containment band 106.The handle structure 108 may be in a form of continuous structure thatcompletely surrounds the containment band 106. Alternatively, the handlestructure 108 may be in a form of a plurality of intermittent structuresthat are spaced around the containment band 106. For instance, two ormore (e.g., three, four, five, six, seven, eight, etc.) intermittentstructures may be evenly spaced around the containment band 106,although example embodiments are not limited thereto. The length of theintermittent structures may be relatively long so as to be greater thanthe space between them. In another example, the length of theintermittent structures may be relatively short so as to be less thanthe space between them.

FIG. 2 is a schematic view of a compression phase of a method ofremoving salt from a dendritic mixture using a mechanical press systemaccording to an example embodiment. Referring to FIG. 2, the dendriticmixture 102 is subjected to heat and compression by the upper press body120 and the lower press body 110. The heat is provided by at least thefirst heater 122, second heater 116, and third heater 118. Although FIG.2 shows the upper press body 120 as having one heater and the lowerpress body 110 as having two heaters, it should be understood thatexample embodiments are not limited thereto. The heating of thedendritic mixture 102 may begin during the loading state via the lowerpress body 110. Alternatively, the heating of the dendritic mixture 102may be postponed until the compression state such that the heating isinitiated by both the upper press body 120 and the lower press body 110.

The upper press body 120 may be configured to be stationary, while thelower press body 110 may be configured to move toward the upper pressbody 120 in a second direction 119 during the compression state (FIG. 2)and to move away from the upper press body 120 in a fifth direction 135during the decompression state (FIG. 3). However, it should beunderstood that example embodiments are not limited thereto. Forinstance, the configuration may be reversed, with the upper press body120 being moveable and the lower press body 110 being stationary.Furthermore, both the upper press body 120 and the lower press body 110may be moveable. The compression of the dendritic mixture 102 by theupper press body 120 and the lower press body 110 may occur continuouslyor in stages. For example, compressing in stages may include a firststage where the upper press body 120 and the lower press body 110 aremoved toward each other to exert a first pressure on the dendriticmixture 102, followed by a pause while maintaining the heating and firstpressure, and then a second stage where the upper press body 120 and thelower press body 110 are moved even closer together to exert a greatersecond pressure on the dendritic mixture 102, etc.

The curved bottom portion of the upper press body 120 may have a shapethat corresponds to a partial surface of a sphere. The upper lip portionof the upper press body 120 is angled so as to point toward thecontainment band 106 during the compression state. For example, theupper lip portion of the upper press body 120 is angled downwards andoutwards toward the containment band 106 during the compression state.The size and shape of the upper press body 120 and the containment band106 are configured such that the upper press body 120 will fitrelatively closely within the interior of the containment band 106during the compression state. The fit should be adequate such that onlya relatively small amount (if any) of the dendritic mixture 102 willforced out from between the upper press body 120 and the containmentband 106 during the compression state.

As a result of the heat and compression, the salt within the dendriticmixture 102 will melt and drain away from the upper press body 120 andthe lower press body 110 in the form of a fluidic mixture 124. Thefluidic mixture 124 includes the molten salt along with residualmetallic dendrite of a relatively small size that managed to passbetween the containment band 106 and the lower press body 110. Thefluidic mixture 124 may be filtered by a sieve 114 that hasholes/openings/perforations that are smaller than an average particlesize of the residual metallic dendrite so as to capture the residualmetallic dendrite 126 while allowing the molten salt 128 to pass. Themolten salt 128 may be recycled for reuse in an electrolytic reductionsystem. The sieve 114 may have a shape that corresponds with theperiphery of the lower press body 110. For instance, in an example wherethe periphery of the lower press body 110 is round, the sieve 114 may bering-shaped.

FIG. 3 is a schematic view of a decompression phase of a method ofremoving salt from a dendritic mixture using a mechanical press systemaccording to an example embodiment. Referring to FIG. 3, after thecompression phase has been deemed to be complete, a support arm 130 isconfigured to extend in a third direction 132 and fourth direction 134toward the containment band 106 and engage the handle structure 108. Thesupport arm 130 may include as many members as needed to support and/orstabilize the containment band 106. The support arm 130 may also beconfigured to move the containment band 106. During the decompressionphase, the lower press body 110 is moved in a fifth direction 135 awayfrom the upper press body 120, thereby exposing the ingot 144 on thelower press body 110.

A receiving structure 136 is configured to extend in a sixth direction138 toward the lower press body 110 such that the top portion of thelower press body 110 is aligned with an upper surface of the receivingstructure 136. A plow 140 is configured to move in a seventh direction142 across the top portion of the lower press body 110 so as to transferthe ingot 144 onto the receiving structure 136. The ingot 144 andresidual metallic dendrite 126 may be subjected to further processing(e.g., processing pertaining to fuel fabrication).

According to an example embodiment, a method of removing salt from adendritic mixture includes loading the dendritic mixture into amechanical press system. The dendritic mixture may be in a form of anelectrolytically-reduced cake. The dendritic mixture may include ametallic dendrite and salt dispersed within the metallic dendrite. Themetallic dendrite may include at least one of plutonium and uranium. Thesalt may be lithium chloride. The dendritic mixture is heated to liquefythe salt without volatilizing one or more metals of the metallicdendrite. For example, the heating may be performed at a temperaturethat does not exceed about 650 degrees Celsius (e.g., 605 to 630 degreesCelsius), although the temperature may vary depending on the meltingpoint of a particular salt and the boiling point of a particularcontaminant (e.g., americium (Am)). In particular, the temperatureshould be above the melting point of the salt but below the boilingpoint of the contaminant in the dendritic mixture. The dendritic mixtureis also compressed to obtain a fluidic mixture and an ingot of themetallic dendrite. The fluidic mixture may include molten salt andresidual metallic dendrite. As a result, the fluidic mixture may befiltered to separate the residual metallic dendrite from the moltensalt.

The mechanical press system may be formed of materials that act asneutron absorbers (e.g., boron, cadmium, hafnium). By using neutronabsorbing materials, larger batch sizes and more throughput arepossible, since a greater amount of dendritic material may be loadedinto the mechanical press system without criticality concerns. Unlikethe conventional art, the system and method of the present disclosuredoes not involve a cathode processor. Consequently, the system andmethod of the present disclosure are simpler and cheaper in design andoperation.

While a number of example embodiments have been disclosed herein, itshould be understood that other variations may be possible. Suchvariations are not to be regarded as a departure from the spirit andscope of the present disclosure, and all such modifications as would beobvious to one skilled in the art are intended to be included within thescope of the following claims.

1. A mechanical press system comprising: an upper press body including acurved bottom portion and an upper lip portion surrounding the curvedbottom portion; a first heater within the upper press body; a lowerpress body aligned below the upper press body, the lower press bodyincluding a top portion and a lower lip portion surrounding the topportion, the upper press body and lower press body configured to cometogether during a compression state and configured to move apart duringa decompression state; a second heater within the lower press body; anda containment band configured to rest on the lower lip portion of thelower press body and to surround the upper lip portion of the upperpress body during the compression state and configured to separate fromthe upper press body and the lower press body during the decompressionstate.
 2. The mechanical press system of claim 1, wherein the curvedbottom portion of the upper press body has a shape that corresponds to apartial surface of a sphere.
 3. The mechanical press system of claim 1,wherein the upper lip portion is angled so as to point toward thecontainment band during the compression state.
 4. The mechanical presssystem of claim 1, wherein the top portion and the lower lip portion ofthe lower press body form a notch therebetween, the notch configured toreceive the containment band during the compression state.
 5. Themechanical press system of claim 1, wherein the containment bandincludes a handle structure on an exterior surface of the containmentband.
 6. The mechanical press system of claim 5, further comprising: asupport arm configured to extend toward the containment band and engagethe handle structure during the decompression state.
 7. The mechanicalpress system of claim 1, further comprising: a sieve aligned below aperiphery of the lower press body.
 8. The mechanical press system ofclaim 1, further comprising: a plow configured to move across the topportion of the lower press body during the decompression state.
 9. Themechanical press system of claim 1, further comprising: a receivingstructure configured to extend toward the lower press body during thedecompression state such that the top portion of the lower press body isaligned with an upper surface of the receiving structure.
 10. Themechanical press system of claim 1, wherein the upper press body isconfigured to be stationary, and the lower press body is configured tomove toward the upper press body during the compression state and tomove away from the upper press body during the decompression state. 11.A method of removing salt from a dendritic mixture, comprising: loadingthe dendritic mixture into a mechanical press system, the dendriticmixture including a metallic dendrite and the salt dispersed within themetallic dendrite; heating the dendritic mixture to liquefy the saltwithout volatilizing one or more metals of the metallic dendrite; andcompressing the dendritic mixture to obtain a fluidic mixture and aningot of the metallic dendrite, the fluidic mixture including moltensalt and residual metallic dendrite.
 12. The method of claim 11, whereinthe loading the dendritic mixture includes the dendritic mixture beingin a form of an electrolytically-reduced cake.
 13. The method of claim11, wherein the loading the dendritic mixture includes the metallicdendrite including at least one of plutonium and uranium.
 14. The methodof claim 11, wherein the loading the dendritic mixture includes the saltbeing lithium chloride.
 15. The method of claim 11, wherein the heatingis performed at a temperature that does not exceed about 650 degreesCelsius.
 16. The method of claim 11, wherein the method of removing saltdoes not involve a cathode processor.
 17. The method of claim 11,further comprising: filtering the fluidic mixture to separate theresidual metallic dendrite from the molten salt.